LED warning lamp changes color as rooms get noisier
Behavioral economics in practice. Every school should have one of these.
It can get tiresome, continually having to tell groups of children – or even adults – to be quiet. That’s where a new sound-sensitive lamp comes in, as it does the job for you by changing color in response to rising noise levels.
https://newatlas.com/good-thinking/led-lamp-changes-color-noise/
https://newatlas.com/good-thinking/led-lamp-changes-color-noise/